The present invention relates to an apparatus for mounting electronic parts and which is used in the mounting of microelectronic parts into an electronic circuit base plate.
Generally, there has been used a method comprising the steps of applying a bonding agent on the necessary locations of the circuit base plate, sequentially feeding the electronic parts onto the circuit base plate to bond them during the mounting operation, on the electronic circuit base plate. The parts can be leadless type microelectronic parts such as chip type resistors, chip type layer-built capacitors or the like. The circuit base plate with the electronic parts bonded thereon is electrically connected with solder dip.
An example of the prior art parts mounting apparatus is already disclosed in, for example Japanese Laid-open Patent Publication No. 59-86299 and is schematically shown in FIG. 1 of the accompanying drawings. as shown in FIG. 1, a plurality of suction nozzles E are intermittently moved in a circle, and the parts F are sequentially picked up and retained at a parts pickup or receiving position A and set in a first stop position, and are fed to a parts mounting position D, and have their positions adjusted in a first direction by a first position regulating means G at an intermediate stop position of the suction nozzle E along the circle and have their positions adjusted in a second direction by a position regulating means H which is provided at the next intermediate stop position of the suction nozzle E, the second direction being normal to the first direction and the two directions being at right angles to the center of the nozzle E so that the parts F retained on the nozzles are successively acted on to adjust their positions, and thereafter a bonding agent is applied to the parts F at the further intermediate stop position C.
As described hereinabove, the positional adjustment necessary for the parts mounting, and the bonding agent application in the respective stop positions during the period when the parts are intermittently fed from the receiving position to the mounting position allows the required number of operations to be sequentially performed with respect to the feed parts without any time lag or time extension because of the simultaneous necessary individual operatiosn at the respectively disposed suction nozzle stop stations for the number of the operations.
In the case of the prior art, only the operations such as positional adjustment in two directions at right angles to the nozzle on which the parts are held, and the bonding agent application to the parts are performed. But in the operation of handling small electronic parts 1.25 mm in width, 2 mm in length, and 0.5 mm in thickness, the electronic parts may be oscillated, laterally turned, or turned from side to side during the feeding process, during the waiting for the performance of an operation or by air currents. These facts may make the posture of the parts held on the suction nozzle uncertain, so that the parts may be tilted, laterally turned, or turned from side to side with respect to the proper posture. Thus, these parts may be mounted on the circuit board or the like with these parts still in an improper posture even after the parts have been adjusted in two directions. Once a part has been mounted in an improper posture, the entire unit such as the printed circuit board or the like becomes an unacceptable product, so that it must be discarded or one of the complicated microparts must be replaced, thus resulting in a lot of disadvantages.